June 17 2016. The September 1, 2016 issue of Colloids and Surfaces B: Biointerfaces published the finding of researchers at Iran's Tabriz University of Medical Sciences of an ability for the hormone melatonin to improve the effectiveness of tamoxifen, a drug used to treat breast cancer. The discovery could help lower the dose of tamoxifen needed to effectively treat the disease.

The study evaluated the effects of nanostructured lipid carriers loaded with melatonin in an estrogen and progesterone receptor positive breast cancer cell line.

The carriers were used to ensure a slow release of melatonin, which normally has a short life in the body. While melatonin alone reduced cell proliferation by an average of 15%, the hormone added to tamoxifen resulted in doubling of the percentage of cells that underwent apoptosis (programmed cell death).

Combining melatonin with tamoxifen could help avoid some of the potentially serious side effects related to tamoxifen therapy by enabling the administration of a lower dose. Lower doses of tamoxifen could also help delay the development of treatment resistance. "We tried to solve both issues by putting melatonin into nanostructures so they can help the chemotherapeutic agent kill more cells," explained corresponding author Dr. Nasser Samadi, from Tabriz University of Medical Sciences. "By doing this, you can decrease the dose of tamoxifen needed, reducing the severity of the side effects."

"Lots of nanostructures these days are toxic to the body or to other cells, but we found no significant toxicity in the empty nanostructured lipid carriers," he noted. "The characteristics are very suitable for applying to these kinds of treatments."

Dr Samadi and colleagues plan to test nanostructured lipid carriers in other types of cancer prior to evaluating their effects in animals and humans.